Keep it simple
When creating a favicon, it is good to consider it as a kind of extension of your logo. It must mirror your brand image. That means you must consider space. You want to make sure it is bright and attractive. If you have a word-based logo for your brand and want to stay totally authentic to that, it’s best to create a favicon with the first letter of the word. It’s also important to keep the core elements intact for the same look, feel, and cohesiveness.
If you have a brand mark logo, spacing is also an issue. These are the best representations, as you may not have to do much. An iconic logo has both a brand mark and a wordmark. In these cases, just the brand mark is usually used for the favicon. Browser compatibility is also a factor as they all have different requirements. Always remember to keep in mind the favicon’s size.
Represent your brand
This is a representation of your brand and should be cohesively aligned with your colors and strategy. This visual should continue as part of the website using your brand voice and visual language. The color scheme should effortlessly blend into the design. Your favicon may be displayed on different backgrounds that may vary from what you are used to. Testing the favicon on black, gray, and white backgrounds is important before you finalize the design. This will avoid having to do additional work.
Text should be avoided at all costs. With the favicon being so small, it will be very difficult to read what the favicon says. Utilizing the first letter of the brand name in a word logo is smart and can be designed to add an additional flair to the brand. If text must be used, it should be one to three characters only. If you can use initials to get the same effect, this is also a good idea. The goal is to strengthen—not diminish—the brand.